Write to a file in Python

To write a text file, open it in write mode ("w") and call .write() on the file object. If the file does not exist, Python creates it. If it does exist, its old contents are deleted first.

The program

with open("notes.txt", "w", encoding="utf-8") as f:
    f.write("Ada Lovelace\n")
    f.write("Grace Hopper\n")
    f.write("Alan Turing\n")

print("Written to notes.txt")

# read it back to check
with open("notes.txt", encoding="utf-8") as f:
    print(f.read(), end="")

Written to notes.txt
Ada Lovelace
Grace Hopper
Alan Turing

How it works

• open("notes.txt", "w") opens the file for writing. The with block closes the file when the block ends, even if an error happens inside it. Closing the file writes any text that Python is still holding back to the file.
• .write() does not add a new line for you, unlike print(). That is why each string ends with \n.
• encoding="utf-8" makes the file the same on every operating system. Without it, Windows may use a different encoding, and names like "Zoë" can be saved wrongly.
• end="" on the last print() stops it adding a second new line, because the text from the file already ends with one.

Writing a list of lines

writelines() writes every string in a list. It also does not add new lines, so add them in the loop:

names = ["Linus", "Hedy", "Margaret"]

with open("names.txt", "w", encoding="utf-8") as f:
    f.writelines(name + "\n" for name in names)

with open("names.txt", encoding="utf-8") as f:
    print(f.read(), end="")

Linus
Hedy
Margaret

You can also use print(name, file=f), which writes the text and the new line in one call.

Related programs: Append to a file.